Answer: Glial cells called ASTROCYTES help maintain the blood-brain barrier, whereas SCHWANN CELLS create the myelin that envelopes axons
Explanation: Glial cells are specialized cell that are found in both central and peripheral nervous systems, that surrounds the neurones, providing them with support and insulation. There are different types of Glial cells these includes:
- Astrocytes: they maintain the blood brain barrier.
- Schwann cells: create the myelin that envelopes axons of the peripheral nervous system neurones.
- satellite cells: These cells help regulate the external chemical environment of neurones.
- Microglia: they clean up cellular debris through phagocytosis.
- Oligodendrocytes: create the myelin that envelopes axons of the central nervous system
<u>Answer</u>: Sperm cell
<u>Explanation</u>:
Amongst all the 4 options given, only the Sperm cell is a gamete (sex cell) while all the three are somatic cells.
- A <em>somatic</em> cell is the one which forms the body of an organism and contains all the genetic information.
- A <em>gamete</em> is the one which is required for the purpose of fertilization. A gamete of male fuses with the gamete of female in a process called fertilization to form a zygote to give rise to a new individual.
- A Sperm cell is basically a <em>male gamete.</em> It contains only half the amount of genetic information as the other half is contributed by the female gamete.
- This difference in the amount of genetic information arises due to the type of cell division that occurs. The somatic cells undergo mitosis whereas a gamete requires meiosis to occur for its formation.
- During mitosis there is a single round of cell division which divides the parent cell into two daughter cells each with the <em>complete genetic information</em>.
- During meiosis the cell undergoes two rounds of cell division such that a total lf 4 cells are produced each <em>with half the amount of genetic material </em>as present in the parent cell.
Since, <em>sperm is a male gamete and is formed by meiosis it contains only half the genetic information as compared to the other cells.</em>
Photosynthesis is the process taking place in plants that uses water and carbon dioxide to produce oxygen and glucose. The thykaloid membrane is the place where light-dependent reactions take place. In this organ, ATP is released or given off.Hence the answer to this problem should be B
Answer: In diagram B, the magma here is observed to be within the crust and could not come out to the surface. This signifies that the hot, rising magma, suddenly cooled down forming a huge block of mass which is considered to be an intrusive igneous body. It can be a batholith, lacolith or a pluton. This type of body is formed due to the cooling and the consolidation of hot magma.
